Two of the most popular conventional handlebar designs in general use are the aero and ram-type handlebars; and the ram-type handlebars are standard equipment on most bicycle models. In both designs two parallel, forward extending hand grips are spaced narrowly apart and located at a relatively high position, thereby urging the cyclist into a more upright position on the bicycle. This is sufficient for lower speed, recreational cycling, but because the cyclist will have a relatively large frontal area exposed, drag force will result that becomes increasingly significant at higher speed, e.g. above approximately 30 M.P.H. Also, another significant drawback of this design is that the posture of the cyclist during riding creates a pocket in front of and below the cyclist's shoulders that traps air and results in a continuous drag force that becomes increasingly significant at higher speeds.
Both type handlebar designs do not allow for optimum cranking leverage by the cyclist. The optimum cranking leverage is the greatest force possible that can be applied to the pedals of a bicycle for greater torque and increased bicycle speed all due to an optimal positioning or posture of one's body parts.
The cranking leverage afforded by the ram-type handlebars is not optimum, and the cyclist is subject to discomfort and fatigue, because the weight of the cyclist's upper body is supported primarily through his arms which are in a continuous state of muscular exertion. Also the positioning of the ram-type and aero handlebars, when used with a standard handlebar stem, may interfere with the cyclist's knees and/or thighs during vigorous cranking, as during start-up or climbing. This is particularly the case of competition bicycles which have a smaller wheel base or which otherwise have the saddle positioned closer to the handlebar assembly.
This is an improved design for longer distance cycling and short competition racing, because the cyclist's upper torso is bent downward. This decreases the amount of frontal area exposed, thus reducing the air drag force and improving the cyclist's cranking leverage relative to a cyclist using ram-type or aero handlebars.
In an attempt to solve some of these problems in the conventional ram-type handlebars, the so-called "aero" bar was developed as an attachment to the handlebars. In the aero bar design, the hand grips are located forward of the bicycle handlebar stem and spaced relatively close together. The hand grips typically are connected together at their forward ends to form a generally wedge shaped, forward pointing handlebar construction. Because the hand grips are positioned further forward than the hand grips in conventional ram-type handlebars, a cyclist will lean forward to a greater extent, thus reducing his or her frontal surface area and moderately decreasing the air drag. However, because the cyclist's arms are positioned relatively close together, the cyclist's upper torso or body cannot be positioned lower to eliminate the drag-generating air pocket it causes or stop the muscle strain of having to raise one's thighs so close to one's stomach. Also, unlike the ram-type handlebar design, the aero bar design is not legal for mass start racing events.
Notwithstanding the improvements provided by the aero bar design in some areas, it still does not achieve optimal cranking leverage, respiration, speed, comfort, and safety. It strives for only a streamlined frontal surface or area, and sacrifices in stability and safety are made.